Protein disulfide isomerase gene family and its potential function on Endoplasmic Reticulum quality control in Diatom Phaeodactylum tricornutum

Abstract PDI was a molecular chaperone and played an important role in Endoplasmic Reticulum quality control (ERQC). PDI chaperone participated in the refolded of the misfolded/ unfolded proteins to maintain the cellular homeostasis under different stresses. However, bioinformatic characteristics and potential functions of PtPDIs in diatom Phaeodactylum tricornutum were still unknown so far. Hence, the genome-wide characterization of PtPDI proteins in P. tricornutum was firstly studied via bioinformatic and transcriptomic methods. Totally, 42 PtPDI genes were identified from the genome of P. tricornutum . The motifs, protein structure, classification, the number of introns-exons, phylogenetic relationship, and the expression level of 42 PtPDI genes under the tunicamycin stress were analyzed. The PtPDI genes in P. tricornutum were divided into three individual branches, indicating different evolutional relationships of these PtPDIs. The 14 up-regulated PtPDI genes under the tunicamycin treatment might have a positive effect on the ER quality control of the unfolded/ misfolded proteins, while the 7 down-regulated PtPDIs might negative effect the ERQC. Anyway, the important functions of PtPDIs in the ERQC of P. tricornutum still need more experiments to clarify. The study here provides a comprehensive understanding of the genome wide PtPDIs gene family and will be important for the functional study of PtPDIs in the ERQC.